1. Field of the Invention
This invention relates to apparatus for accommodating cargo and disabled persons, and more particularly, to an apparatus for lowering the body of a motor vehicle to allow physically disabled persons to embark and debark comfortably and to allow cargo to be loaded and unloaded easily. The Americans with Disabilities Act (ADA) requires that, by Jan. 26, 1997, all public transportation, including taxis, hotel shuttles, etc., be equipped to accommodate physically disabled person, such as those confined to wheelchairs.
2. The Prior Art
Mechanical difficulties are inherent in providing access between the body of a motor vehicle and the street. Several solutions have been proposed.
These solutions often involve the use of ramps. One problem with a ramp is that the angle of incline of the ramp may be much too steep for carrying heavy cargo easily or for the average wheelchair to traverse easily. A solution to this problem is to modify the vehicle by permanently lowering the vehicle floor. In this case, the ramp traverses the reduced height between the ground and the floor of the vehicle. However, problems arise with this solution. First, the modifications in the vehicle construction necessary to lower the floor of a motor vehicle are substantial. Many components of the vehicle must be repositioned, the existing floor must be removed, and a new floor installed. The time and effort involved are substantial and costly. Also, such redesign involves issues of safety. For example, in some vehicle models, the fuel tank must be relocated. Since the automotive manufacturers locate fuel tanks to be as protected as possible during collisions, moving the fuel tank may make it more susceptible to damage during a collision.
Another safety issue is involved in lowering the floor of the vehicle. Because the floor is permanently lowered, it is more susceptible to "bottoming out," in which case the bottom of the vehicle floor hits the road when going over bumps and potholes. This factor can lead to vehicle control problems, as well as reduction of the maximum load that the vehicle can safely carry. A further safety issue involves the integrity of the vehicle body itself. Many vehicles are designed without a heavy frame on which to mount the body components. They rely instead on the combination of the body components themselves to give structure to the body (the "unibody" construction). The integrity of the unibody may be compromised by removing and replacing a substantial portion of the vehicle floor. The vehicle body may tend to become more susceptible to collapse because it no longer conforms precisely to the manufacturer's design.
An alternative solution is to install a special suspension system by which the body may be lowered. Typically, this type of system may consist of suspension devices that are inflated or deflated by air to raise or lower the floor of the vehicle. The main drawback of a special suspension system is the necessity of replacing or substantially modifying the original factory-installed suspension system, thereby increasing cost and complexity.
Thus, there continues to be a need for a system for lowering the floor of a vehicle to permit a load to ingress and egress easily and comfortably that can overcome the above-described drawbacks of the prior art.